Which of the following Linux commands can change both the username and group name a file belongs to?

chown changes the user owner of a file and can optionally set the group with colon syntax (chown user:group), but it is primarily associated with changing user ownership rather than being dedicated to group changes.

chgrp (change group) is the Linux command dedicated specifically to changing the group name (group ownership) associated with a file or directory. It directly modifies the group ownership field in the file's inode, accepting a group name or GID and one or more target files as arguments.

chmod modifies the read, write, and execute permission bits on a file and has no effect on user or group ownership metadata.

newgrp changes the active group ID for the current shell session, affecting group ownership of newly created files going forward, but does not modify ownership of any existing files.